Apparatus to emulsify a liquid in a gas by means of ultrasonic vibrations



June 13, 1967 G. E. BRODERS 3,325,150 APPARATUS TO EMULSIFY A LIQUID IN A GAS BY MEANS OF ULTRASONIC VIBRATIONS Filed Sept. 23, 1964 2- Sheets-$heet 1 25 O O O INVENTOR JACQUES GEORGES [SD/0N? BRODERS ATTORNEYS United States Patent Office 3,325,150 APPARATUS T EMULSIFY A LIQUID IN A GAS BY MEANS OF ULTRASONIC VIBRATIONS Jacques Georges Edmond Broilers, Paris, France, assignor to Societe dEtudcs et dUtilisatien rle Dechets Industriels et Agricoles (Seudia), Siene, France Filed Sept. 23, 1964, Ser. No. 398,652 Claims priority, application France, Sept. 28, 1963, 949.0% 3 Claims. (Cl. 2591) The present invention is concerned with an apparatus for producing emulsions of liquids in gases or vapors by ultrasonic vibrations.

An object of the invention is to cause the stabilisation of said emulsions and a further object of the invention is to bring about desired chemical reactions between these liquids and gases under the helping effect of the state of extreme division in which the emulsion is thus obtained.

Examples of the use of the apparatus for accomplishing one or all of the above objects is in the production of mineral oil emulsion such as, for instance, asphalt emulsions, the saponification of fatty materials emulsified in water vapor, the sulfonation of organic products emulsitied in sulfuric anhydrid diluted in an inert gas, the purification of oils, fats or resins, the pyrolysis of fatty acids and of glycerides, the ozonolysis of unsaturated fatty acids to obtain, among others, saturated monoand diacids such as azelaic acid from oleic acid treated with ozonised oxygen, and many other manufactures of great technical interest.

It is known to produce ultrasonic vibrations by means of whistles in which the flow of a fluid under pressure is injected through a small orifice tangentially into a cavity of a practically circular section in which the fluid travels in a circuit and reacts upon the injected flow to produce ultrasonic vibrations.

It is also known to provide whistling cavities in very thin stacked plates with intermediary separating plates which laterally limit these cavities. The apertures which afford passage for the fluid under pressure into the whistling cavities are then small holes about as wide as they are high. It has been suggested to apply these generators of ultrasonic vibrations to the mixing of fluids, and the fluids to be mixed were to be led through similar or identical whistles. Such a procedure would require very high feeding pressures reaching, for instance, several tens of bars.

Such apparatuses require an excessive expenditure in energy to feed the fluids under pressure and are definitely to be barred from certain applications and especially from the ozonolysis of oleic acid because of the explosion hazard caused by compressing ozonised oxygen.

In contradistinction to the installations previously disclosed, the subject invention has as an object to produce an emulsion of a liquid in a gas by using the gas to generate the ultrasonic vibrations while feeding this gas at a very low pressure which is generally under 1 bar or little more than 1 bar. This is achieved by injecting this gas through a very fine slot about 0.1 mm. wide and about 1.5 cm. high. It has been noticed that reducing the width of the slot allowed a maximum acoustic pressure with a lower feeding pressure. With a width of the slot of 0.1 mm, this maximum acoustic pressure, of several millibars or hundreds of newtons per square metre, is obtained with a feeding pressure of less than one bar.

With the above objects in view, according to the invention, whistling cells in the form of blocks are used to bring about the sound vibration of the gas. These blocks have preferably a height of about 1.5 cm. for sound frequencies of 12,500 cycles per second and have along their entire height a narrow slot provided to inject the 3,325,150 Patented June 13, 1967 gas into a cylindrical whistling cavity which has a diameter of several millimeters and is connected laterally with a larger cavity which is the reaction chamber. This lateral connection is also essentially a slot which extends along theentire height of the cell and is in the vicinity of the first mentioned narrow slot. On the other hand, the liquid is introduced by means of a sprinkling nozzle having a diameter of several tenths of a millimeter, and directed thereby towards one end of the cylinder which forms the Whistling cavity, and injected either into that cavity or into the reaction chamber where the gas submitted to the ultrasonic vibrations also penetrates.

The apparatus according to the invention comprises essentially superimposed whistling cells which are formed as set forth above, each cell being associated with a sprinkler-type liquid distributing plate and these whistling cells being separated from each other by neutral cells. These neutral cells comprise themselves distributing channels like the whistling cells and extensions of the reaction chambers in which any auxiliary conventional devices to guide the mixture in emulsion can be adopted. Such devices will, for instance, maintain the mixture in a state of turbulence all along the outflow duct, this duct con sisting of the succession of the reaction chambers in a line with their extensions. The whistling and neutral cells are assembled together in a unit forming the emulsifying apparatus or a part thereof.

To the unit described above can be added a further reaction apparatus of a larger section in the form, for instance, of a nest of tubes. In these tubes the desired reaction between the reactants can. come to completion priorto submitting the mixture to additional purification or conversion, or using it as is.

The subject invention will be better understood in conjunction with the accompanying drawings in which:

FIG. 1 is a top view of a whistling cell in accordance with the invention;

FIGS. 2 and 3 are top views of two modifications of a distributing plate associated with two different ways for injecting the liquid into the gas;

FIGS. 4 and 5 are top views of two plates, the association of which provides for the distribution of the liquid according to a third way of injecting the liquid;

FIG. 6 shows an exploded sectional perspective view of an active emulsifying assembly consisting of a whistling cell as disclosed in FIGURE 1 and of the two plates as disclosed in FIGURES 4 and 5;

FIG. 7 is a side view of an apparatus according to the invention which comprises superimposed whistling cells of any of the three types mentioned above.

The whistling cell shown in FIGURE 1 comprises a block 1, made of stainless steel, for instance, and having the shape of a straight parallelepiped the bases of which are carefully surfaced to allow the superimposing of distributing plates having the same shape for forming a unit of several cells as set forth below.

Block 1 has two bores or ducts 2 and 3 positioned in a perpendicular relationship to its bases and which admit respectively the gas and the liquid.

Block 1 has furthermore a cylindrical narrower channel 4 which constitutes the whistling cavity and is located between ducts 2 and 3. The duct 2 communicates with the channel 4 by means of a passage 5, this passage connecting in a tangent relationship with the channel 4 by means of a very thin slot 6 the width of which is about 0.1 mm. On the periphery of channel 4 and just after narrow slot 6 in the direction of the gas flow is provided a vertical and somewhat wider slot 7 which connects the channel 4 with a reaction chamber 8, this reaction chamber being also provided in the block l along its entire height.

In the embodiment shown, chamber 8 is confined by a surface 9 shaped as a part of a circular cylinder which faces the channel 4 and is connected with the slot 7 by means of two vertical planes 10 and 10a which are tangent to the edges of the surface 9.

The operation of the whistle described above will be easily understood. The flow of gas coming from duct 2 and passing through passage 5 emerges tangentially under the form of a flat thin stream through the thin slot 6 into the channel 4 in which it travels in a circuit and encounters, after an almost complete round, the flow of gas coming through the slot 6 and interrupts it. This phenomenon reoccurs periodically and produces ultrasonic vibrations the frequency of which is determined above all by the diameter of the channel 4 and the speed ofthe gas flow. The vibrating gas within channel 4, acting as a whistling cavity, escapes from said whistling cavity 4 by means of the slot 7, the width of which can be about a millimeter and pursues its rotating trajectory within reaction chamber 8 while being evacuated in a longitudinal direction with respect to this chamber, in other words in a parallel relationship to the slot 7.

The liquid to be emulsified can be admitted by diiferent injection means, either into the whistling cavity 4 or into the reaction chamber 8. The inlet of this liquid is preferably located near the base of the whistling cell such as described above by means of one or several distributing plates which are applied to the base of the cell.

In the embodiment of FIGURE 2 can be seen a distributing plate 11 in which round apertures 12, 13, 14 and 15 have been provided, these holes being respectively in alignment with ducts 2, 3, 4 and with part of reaction chamber 8. Furthermore between apertures 13 and 14, plate 11 comprises a slot 16 which opens into the aperture 14 by a narrow sprinkling nozzle 17 oriented preferably tangentially with respect to the aperture 14 and in the direction of the gas flow in the channel 4 which is the anti-clockwise direction as viewed in FIG. 1 and 2. It can be seen that the liquid stream ejected from the nozzle 17. is entrained and pulverized by the rotating gas and forms a thin film of liquid on the internal wall of the channel 4 before being entrained by the gas through the slot 7 as a finely divided mist.

This embodiment is particularly adapted to the case where the proportion of liquid with respect to the gas is rather small. Where a larger amount of liquid must be injected, distributing plate 21 of FIG. 3 can be used. This plate has apertures 22, 23, 24 and 25 which are analogous to apertures 12, 13, 14 and 15 of plate 11. The plate 21 comprises furthermore a slot 26 which connects apertures 23 and 25 and emerges tangentially into the aperture 25 in the clockwise direction, as viewed in FIG- URE 3, which is the direction of rotation of the gas flow within the reaction chamber 8 which is in alignment with aperture 25.

Another preferred injection means of the liquid can be obtained by associating the two plates shown in FIG- URES 4 and 5. The distributing plate 31 of FIGURE 5 comprises apertures 32 and 33 in alignment with ducts 2 and 3 and an aperture 35 in alignment with part of the reaction chamber 8. Furthermore, the aperture 33 is extended laterally by a narrow passage 34 the end of which is located on a line parallel to slot 7 in reaction chamber 8 and ahead of slot 7 at a distance thereof of about 1 or 2 mm. Plate 31 is associated with a plate 41 which comprises apertures 42, 43 and 45 which are analogous to apertures 32, 33 and 35 and in alignment with them and further a small additional aperture 46 which acts as a sprinkling nozzel and which is provided to fit over the extremity 36 of passage 34.

As the whistling cell is applied upon the plate 41 and the latter plate on the plate 31, the liquid flow from the nozzle 46 comes out at the base of the reaction cham- 4 her 8 and a little ahead of slot 7 and meets the gas stream flowing from channel 4 into chamber 8.

Behind the nozzle 46 in an opposite position with respect to the slot 7 may be provided a screen 37 formed by a folded and cut out part of plate 31 extending vertically through a corresponding slot 48 in the plate 41 within the reaction chamber 8 of the block for retaining the liquid stream on a line parallel with the slot 7 before being pulverized and entrained by the gas stream..

When several cells are superimposed along with their liquid distributing plates, neutral cells are inserted which are similarly provided with apertures or bores in alignment with ducts 2 and 3 and chambers 8 so that the portion of ducts 2 and 3 form continuous conduits and the same is valid for the reaction chambers through which the outflow of the emulsified products is obtained. On the contrary, the various whistling cavities 4 are isolated from each other. The heights of the active cells and of the neutral cells are calculated to maintain the vibration correctly in phase.

FIG. 7 shows a complete apparatus according to the invention for the obtention of a desired chemical reaction by means of emulsification under the action of ultrasonic vibrations. A number of active cells 51 have been superposed and associated with neutral cells 52 and liquid distributing plates 53 in accordance with what has been set forth above. This assembly is held between two flanges 54 and 55 connected with feeding ducts 56 and 57. The row of the reaction chambers with their extensions in the neutral cells forms a duct 58 which in the present embodiment is connected with a nest of tubes 59 in which the reaction which has started in the cells can be brought to completion. The final product is led out through the outlet 60. 1

If desired, sealing rings or washers can be added between the different cells or plates of the unit consisting of superimposed cells.

It is to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention. For example, whereas the active cell was disclosed as a block having a height of about 1.5 cm., it will be recognized that, for convenience in manufacturing such a block, the same can consist of several parts which are thereafter bonded together in a block of an active cell as disclosed.

I claim:

1. A whistling cell for emulsifying a liquid in a gas by means of ultrasonic vibrations, comprising a block with two parallel plane base surfaces, a gas inlet bore and a liquid inlet bore arranged through said block perpendicularly to said surfaces for admitting respectively the gas and the liquid, a channel of approximately circular section through said block for operating as a Whistling cavity, a passage extending through the whole height of said block between said gas inlet bore and said channel and in communication with said channel through a thin slot of about 0.1 mm. arranged for injecting a fiat thin stream of gas tangentially into said channel, a reaction chamber extending through the whole height of the block in a direction parallel with that of said channel and in communication with said channel through a second larger slot arranged in the periphery of said channel after said thin slot in the direction of the gas injected into said channel and plate means in contact with one base of said block having apertures in alignment with said inlet gas bore and said inlet liquid bore and further apertures in alignment with said channel and said reaction chamber, and a passage with a nozzle for injecting the liquid extending from said aperture in alignment with said liquid inlet bore to one of said further apertures.

2. A whistling cell for emulsifying a liquid in a gas as claimed in claim 1 in which said nozzle communicates with the aperture of said plate means in alignment with the stream of gas flowing into said chamber through said said channel and is arranged for directing liquid tangen- Second tially with respect of said channel in the direction of the References Cited stream of circulating gas in said channel. UNITED STATES PATENTS 3. A Whistling cell for emulsifying a liquid in a gas as 5 ,071,14 1/1963 Blanchard 2591 X claimed in claim 1 in which said nozzle communicates 3,108,060 10/1963 Matthews 2594 X with the aperture of said plate means in alignment with 3130452 4/1964 Heumann 2594 X said reaction chamber and is arranged for injecting liquid WALTER SCHEEL, primary Examiner. tangentially into said reaction chamber in the direction of 10 L BELL Assistant Examine]. 

1. A WHISTLING CELL FOR EMULSIFYING A LIQUID IN A GAS BY MEANS OF ULTRASONIC VIBRATIONS, COMPRISING A BLOCK WITH TWO PARALLEL PLANE BASE SURFACES, A GAS INLET BORE AND A LIQUID INLET BORE ARRANGED THROUGH SAID BLOCK PERPENDICULARLY TO SAID SURFACES FOR ADMITTING RESPECTIVELY THE GAS AND THE LIQUID, A CHANNEL OF APPROXIMATELY CIRCULAR SECTION THROUGH SAID BLOCK FOR OPERATION AS A WHISTLING CAVITY, A PASSAGE EXTENDING THROUGH THE WHOLE HEIGHT OF SAID BLOCK BETWEEN SAID GAS INLET BORE AND SAID CHANNEL AND IN COMMUNICATION WITH SAID CHANNEL THROUGH A THIN SLOT OF ABOUT 0.1 MM. ARRANGED FOR INJECTING A FLAT THIN STREAM OF GAS TANGENTIALLY INTO SAID CHANNEL, A REACTION CHAMBER EXTENDING THROUGH THE WHOLE HEIGHT OF THE BLOCK IN A DIRECTION PARALLEL WITH THAT OF SAID CHANNEL AND IN COMMUNICATION WITH SAID CHANNEL THROUGH A SECOND LARGER SLOT ARRANGED IN THE PERIPHERY OF SAID CHANNEL AFTER SAID THIN SLOT IN THE DIRECTION OF THE GAS INJECTED INTO SAID CHANNEL AND PLATE MEANS IN CONTACT WITH ONE BASE OF SAID BLOCK HAVING APERTURES IN ALIGNMENT WITH SAID INLET GAS BORE AND SAID INLET LIQUID BORE AND FURTHER APERTURES IN ALIGNMENT WITH SAID CHANNEL AND SAID REACTION CHAMBER, AND A PASSAGE WITH A NOZZLE FOR INJECTING THE LIQUID EXTENDING FROM SAID APERTURE IN ALIGNMENT WITH SAID LIQUID INLET BORE TO ONE OF SAID FURTHER APERTURES. 